For your consideration.
In what was normal times any building project will take significantly longer than a put on paper due date plan.
Put on paper in terms this statement refers to-
Building lot.
Aproved Building permit.
Architecture drawings and list materials.
Cost and availability building materials
Contractors .
Big bag money or firm financing.
All know that supply issues can drive turds into your punchbowl .
Recently ( last year ) friend had a home built that was supposed to take 1/2 year ( he had all the above). Professional builder. Took 2 years to complete to point occupancy permit.
Hopefully your results will be better.
Best luck your journey.
Be well Shane